Mannitol egg yolk polymyxin (MYP) agar base 500g

GranuCult^® Mannitol egg yolk polymyxin agar (base) is used for the enumeration of Bacillus cereus. This medium contains two indicator systems, mannitol, and phenol red and egg yolk. Enzymatic digest of casein and meat extract provide carbon and nitrogen sources. The selective inhibitory component polymyxin suppresses the growth of many unwanted microorganisms. Bacteria that ferment mannitol to produce acids produce yellow staining of the medium with phenol red as a pH indicator. Bacillus cereus does not ferment mannitol so the medium around the colonies remains unchanged or is discolored due to light alkalization by forming pink colonies. The lecithin present in egg yolk is cleaved by the Bacillus cereus-lecithinase, which leads to the formation of an opalescent white precipitation zone surrounding the pink colonies. Bacillus anthracis, Bacillus mycoides, Bacillus pseudodomycoides, Bacillus thuringiensis, and Bacillus weihenstephanensis may not be distinguishable from Bacillus cereus on this medium.

GranuCult^® Mannitol egg yolk polymyxin agar (base) is used for the enumeration of presumptive Bacillus cereus from food and animal feed as well as from environmental samples and other materials.